Auxiliary tool adapter for electric hand saws having forwardly mounted auxiliary handles

ABSTRACT

A power tool attachment is provided which is adapted to be mounted on a hand-held circular blade power saw, of the type commonly referred to as a &#39;&#39;&#39;&#39;Skil-Saw,&#39;&#39;&#39;&#39; and particularly one which is provided with a forwardly mounted vertically extending auxiliary handle. Alternatively, a vertically extending auxiliary handle is provided in combination with the power tool attachment, which handle may be affixed to the flat bed of the power saw. The attachment itself comprises a clamp member adapted to be fastened to the upper end of the vertically extending auxiliary handle and a mandrel which is clamped to the handle by means of the clamp member. The mandrel is provided with a rotatably mounted shaft and a pulley affixed thereto. The shaft is driven by means of a flexible endless belt engaging the pulley and operated by a second pulley mounted on the motor shaft and engaged by the belt. Means are provided on the end of the shaft for attachment to various rotatable tools, or to a chuck which may be utilized in engaging the shafts of various types of rotary tools.

United States Patent [191 Heisler 1 *July 29, 1975 1 1 AUXILIARY TOOL ADAPTER FOR ELECTRIC I-IAND SAWS HAVING FORWARDLY MOUNTED AUXILIARY HANDLES [76] Inventor: Clarence J. Heisler, 28007 S Dr.,

North, R.R. No. 2, Springport,

Mich. 49284 Notice: The portion of the term of this patent subsequent to July 24, 1990, has been disclaimed.

[22] Filed: Apr. 30, 1973 [21] Appl. No.: 356,050

Related U.S. Application Data [63] Continuation-impart of Ser. No. 107,292, Jan. 18,

[52] U.S. Cl 144/1 E; 144/35 A; 30/388; 30/375; 51/169 [51] Int. Cl. B27e 9/2 [58] Field of Search 144/1 E, l R, 35 A; 51/169, 170; 30/388, 375

[56] References Cited UNITED STATES PATENTS 1,967,163 7/1934 Thearle 51/169 2,544,810 3/1951 Strandberg 144/1 E 3,747,650 7/1973 Heisler 144/1 E Primary Examiner-Donald R. Schran Attorney, Agent, or Firm-Samuel Kurlandsky [57] ABSTRACT A power tool attachment is provided which is adapted to be mounted on a hand-held circular blade power saw, of the type commonly referred to as a Skil- Saw," and particularly one which is provided with a forwardly mounted vertically extending auxiliary handle. Alternatively, a vertically extending auxiliary handle is provided in combination with the power tool attachment, which handle may be affixed to the flat bed of the power saw. The attachment itself comprises a clamp member adapted to be fastened to the upper end of the vertically extending auxiliary handle and a mandrel which is clamped to the handle by means of the clamp member. The mandrel is provided with a rotatably mounted shaft and a pulley affixed thereto. The shaft is driven by means of a flexibleendless belt engaging the pulley and operated by a second pulley mounted on the motor shaft and engaged by the belt. Means are provided on the end of the shaft for attachment to various rotatable tools, or to a chuck which may be utilized in engaging the shafts of various types of rotary tools.

11 Claims, 16 Drawing Figures AUXILIARY TOOL ADAPTER FOR ELECTRIC HAND SAWS HAVING FORWARDLY MOUNTED AUXILIARY HANDLES BACKGROUND OF THE INVENTION This application is a continuation-in-part of copending application Ser. No. 107,292, filed Jan. 18, 1971, entitled Auxiliary Tool Adapter for Electric Hand Saws of the present inventor.

It has long been customary to provide various types of tool attachments to be operated in conjunction with existing power tools in order to render the power tools more versatile. The most common have been the various attachments designed to be used together with an electric drill. However, such applications have the disadvantages that ordinarily the motors utilized for powering hand-operated drills are not exceptionally powerful. Moreover, such drills do not normally have means for varying the speed of the attachment or means for holding and bracing the assembly in use. More recently, power tool attachments have been provided for use with chain saws since such saws generally have powerful motors. However, it is generally quite dangerous to operate such equipment, since it is normally difficult to remove the cutting teeth-bearing chain when it is desired to operate the equipment in conjunction with a power attachment.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a power tool attachment designed to be utilized in combination with a hand-held portable circular power saw.

It is an additional object to provide an attachment of the type described which may be readily attached to any type of hand-held circular power saw having a base.

It is still another object to provide a power saw attachment of the type described which may be used to rotate tool attachments at various speeds.

It is still another object to provide a power saw attachment which may be readily adapted for use in carrying out a variety of functions under safe conditions.

It is still another object to provide an attachment for a power saw which is relatively simple and inexpensive to build and to operate.

It is still another object to provide a novel hand-held power-operated circular saw having integral means provided upon which power tool attachments may be mounted.

It is still further an object to provide an attachment of the type described for use with power saws having a plate-form vertically extending auxiliary handle affixed to the base plate of the saw.

It is still further an object to provide an attachment for a power saw comprising a sheet-form auxiliary handle which may be affixed to the base plate of a hand saw in vertically extending position, and to cooperate with a clamp member and mandrel to provide an attachment for the power saw.

Still further objects and advantages of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, consists of the useful power tool attachment herein fully described and particularly pointed out in the claims, the annexed drawings, and the following description setting forth in detail certain illustrative embodiments of the invention, such disclosed embodiments illustrating, however, but several of the various ways in which the principle of the invention may be used.

BRIEF DESCRIPTION OF THE DRAWINGS In the annexed drawings:

FIG. 1 is a top plan view of the power tool attachment of the invention mounted on a hand-held poweroperated circular saw.

FIG. 2 is a side elevational view of the apparatus shown in FIG. 1.

FIG. 3 is a side elevational view of the power tool attachment shown by itself.

FIG. 4 is a top plan view of the power tool attachment shown in FIG. 3.

FIG. 5 is a cross-sectional view taken at the line VV of FIG. 4, looking in the direction of the arrows.

FIG. 6 is a cross-sectional view taken at the line VIVI of FIG. 4, looking in the direction of the arrows.

FIG. 7 is a side elevational view of the apparatus shown in FIG. 2, taken from the other side.

FIG. 8 is a side elevational view of another embodiment of the present invention, with a removable portion thereof shown in broken lines.

FIG. 9 is an elevational view partly in cross-section, showing a sub-assembly portion of the invention shown in FIG. 8.

FIG. 10 is a perspective view of a hand-held power saw adapted for use with another embodiment of the invention.

FIG. 11 is a perspective view of the handle and power saw attachment of FIG. 10, but in demounted form, and which may be mounted directly on the base of a power saw which does not have an integral auxiliary handle.

FIG. 12 is an elevational view of a bolt and wing nut combination which may be utilized with the structure shown in FIGS. 10 and 11.

FIG. 13 is a top view of a mandrel having a loop-form handle affixed thereto.

FIG. 14 is a side elevational view showing the saw of FIG. 10 with the power tool attachment of the present invention mounted thereon.

FIG. 15 is a fragmentary view of a structure according to the invention such as shown in FIG. 10 with a mandrel mounted therein, and

FIG. 16 is a fragmentary edge view of the upper portion of another form of auxiliary handle having a power tool attachment including a mandrel mounted therein.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more particularly to FIGS. 1-7, the apparatus shown comprises a power tool attachment 10 mounted on a hand-held power-operated circular saw 11. The saw 11 comprises a motor 12 having a rotatable shaft 13 and a pulley 23 mounted thereon. The motor 12 is mounted on a base 24 by means of a pivoted mounting bracket 14 pivotally supported at its end by engagement with a pin 15 supported by a trunnion 16. The motor is supported at the rear by a brace 17, FIG. 7, mounted on the base 24. The brace 17 is provided with an arcuate slot 18 which adjustably supports the motor 12 by means of a thumbscrew 19. A handle 20 is affixed to the motor. The saw II also has a conventionally provided fixed guard 21, FIGS. 1 and 2, and spring loaded pivoted guard 22, FIG. 7.

The power tool attachment 10, as shown in greater detail in FIGS. 3-6, inclusive, comprises a base 25, FIG. 4, formed of a pair of substantially parallel spaced-apart rails, straps or bars 28 and 29 having a cross brace 30 welded thereto, and a U-shaped handle 31 also welded to the rails 28 and 29. The space between the rails serves as an adjustment slot for the attachment clamping assemblies 41 and 42. The rails 28 and 29 have at one end upturned mandrel supports 33 and 34 having a mandrel sleeve 35 welded to the ends thereof. Mounted in the mandrel sleeve 35, shown in greater detail in FIG. 5, are a pair of bearings 36 and 37, which may be sleeve bearings, roller bearings, ball bearings, or any other suitable type of bearings, and it is intended that the showing be considered as diagrammatically illustrating same. A shaft 38 is journaled in the bearings 36 and 37 and is provided with a threaded end 39 which may engage a chuck 40, shown in FIGS. 1 and 2 or, alternatively, which may directly engage a tool such as a grinding wheel having a fitting with complementary threads integrally provided.

In order to affix the power tool attachment to the saw base 24, clamp assemblies 41 and 42, FIGS. 1 and 2, are provided comprising bolts 43 and 44 whose heads engage the rails 28 and 29 and having shafts extending through the adjustment slots therebetween. The bolts also extend through apertures in arcuate clamp members 45 and 46 and are engaged by wing nuts 47 and 48. Alternatively, steel washers may be used in place of the arcuate clamp members 45 and 46, and it is intended that the showing be considered to diagrammatically illustrate same.

In mounting the present power tool attachment on a saw, the nut which normally holds the saw blade is removed together with the saw blade. The pulley 23 is then attached to the motor shaft 13. The attachment is placed over the base 24 of the saw. As the attachment is brought toward the base 24, the pivoted guard 22 engages the rail 29 and is raised and maintained in the raised position. The adjustable clamps 41 and 42 are moved until the ends of the arcuate clamp members extend over the forward and rear edges of the base 24. The wing nuts 47 and 48 are then tightened sufficiently to clamp the attachment to the saw base. The belt 26 is then engaged over the pulley 23 and the pulley 27. The thumbscrew 19 may be loosened and adjusted in the arcuate slot until the belt is properly tightened. Any suitable tool may be mounted in the chuck 40, FIGS. 1 and 2, or alternatively, directly on the end of the threaded shaft 39. The entire assembly may be grasped by the saw handle and the U-shaped handle 31 and used for any of a large number of operations such as drilling, sanding, grinding, buffing, et cetera. Additionally, by the use of a suitable coupling attachment the apparatus may be used to start lawn mower engines.

Because the motors conventionally utilized in handoperated circular power saws are quite powerful, the apparatus is adaptable for use where ordinary electric drills would not be suitable. Moreover, because a flexible belt connects the motor to the shaft which operates the attachment tools, an element of safety is provided, since the belt permits the pulleys to slide if too great or too sudden a load is applied. Moreover, the speed of the mandrel shaft 38 may be changed by changing the relative sizes of the pulleys 23 and 27. For example,

with a small pulley utilized for the pulley 23, the use of the pulley having a diameter of 5 inches for the pulley 27 will provide about 1,700 revolutions per minute. The use of a 7-inch diameter pulley will result in a speed of about 1,000 r.p.m. Still other speeds may be obtained by the judicious selection of various size pulleys.

The attachment of the present invention greatly increases the versatility of the common hand-supported power circular saw. It permits a large number of attachments to be utilized, provides a great deal of power to drive various attachments, permits the speed of the shaft driving the attachments to be changed to suit the particular use, and permits rapid change from one type of tool to another. Additionally, the unit itself is extremely simple to mount on a conventional power circular saw.

FIGS. 8 and 9 illustrate another embodiment of the invention in which the leg or bracket for supporting the mandrel is manufactured as an integral part of the base of the saw, either as an extension of the base, or else, riveted or bolted thereto. As shown in the drawings, the integral power saw and attachment unit comprises a power saw 51 having a motor 52, a shaft 53, and a pulley 54 mounted on the shaft 53. The motor is pivotally and adjustably mounted at the other end of the base 73 by means of an adjustable bracket 56 mounted at one end to the base and having a slot 57 provided therein. A bolt and wing nut combination 58 clamps the motor in any desired position. The arrangement is useful both for determining the depth of saw cut when a saw blade is mounted on the motor, and additionally for tightening a belt 72 utilized to drive the power attachments. An arbor support 59 is provided as an integral part of the base 73 and is provided with a clamp 60 at its other end comprising a fixed clamp jaw 61, an adjustable clamp jaw 62, and a bolt and wing nut combination 63 for tightening the clamp.

Mounted within the clamp 60 is an arbor 64 comprising a mandrel sleeve 65, bearings 66 and 67, and a shaft 68 journaled in the bearings. A pulley 69 is affixed to the shaft 68 for driving the shaft. The end of the shaft 68 is provided with a threaded end 70 having a chuck 71 mounted thereon. The belt 72 is adapted to be engaged over the pulleys 54 and 69.

The apparatus thus shown in FIGS. 8 and 9 may be utilized in substantially the same ways as that previously shown and described. It is contemplated that the entire unit would be manufactured by the original equipment manufacturer, and could be sold at a price less than the combined price of the saw and separate attachment (described in FIGS. 1-6).

Referring to FIGS. 10-14, an embodiment somewhat similar to that of FIGS. 8 and 9 is shown. In this embodiment a hand-held power saw 78 is shown having a sheet-form auxiliary handle 79 mounted thereon. At the upper end of the handle 79 is a rearwardly oriented arcuate trough or channel serving as a hand grip 80. The hand grip 80 may be grasped during the normal sawing process to provide greater stability. The auxiliary handle 79 is provided with a mounting leg 81 which is affixed to the base plate of the saw, by welding, rivets, or bolts. The plate of the handle member additionally serves in some embodiments to lock the saw in any desired angular position. This is provided by means of an arcuate slot 82 in which a clamping bolt 83 connected to the motor portion of the saw clamps the motor in the desired position. An aperture 84 is also provided in the plate of the handle member for engaging a clamp member 88 shown in FIG. 11. If no such aperture exists it may be subsequently drilled into the plate. The clamp member 88 comprises a plate-form body 89 provided with apertures 90 and a mandrelengaging jaw 91 in the form of an arcuate channel. The clamp member 88 is attached to the handle member 79 by means of bolts 92 and wing nuts 93 (FIG. 12) inserted through the apertures 84 and 88, and through the arcuate slot 82 and aperture 90. A mandrel 94 having a rotating shaft 95 with a threaded end 96 is clamped between the jaw 91 and the handle grip 80, and affixed in place by tightening the wing nuts 93 over the bolts 92, as shown in FIG. 14. A handle 97 is affixed to the mandrel by any process such as welding or bolting to facilitate holding the apparatus during such procedures as boring or sanding.

FIG. 14 illustrates a power tool attachment according to the invention mounted on the base plate 125 of a power saw 126. A pulley 101 is mounted on a mandrel shaft 113 of a mandrel 111, and a pulley 102 is mounted on the shaft 129 of a motor 130. An endless belt 103 operatively connects the two pulleys. Additionally, the structure comprises an auxiliary handle 104 having an arcuate channel-form hand grip 105 at the end thereof and affixed to the base plate 125 by a foot 123 welded thereto. A clamp member 106 comprising a plate 107 and an arcuate mandrel-engaging jaw 108 is affixed to the handle member 104' by means of bolts 109 and wing nuts 110. Clamped between the hand grip 105 and the jaw 108 is the mandrel 111 having bearings 112 supporting a shaft 113 (FIG. The mandrel is clamped in place by tightening the wing nuts 110. The end of the shaft 113 may be threaded for engaging a chuck or various other tools.

Also shown in FIG. 14 is an auxiliary hinge assembly which may be provided for certain purposes. The assembly comprises a hinge plate 131 affixed to a bench 136 by means of bolts 132. I-Iinging is accomplished by means of a hinge member 133 provided on the plate 131 and a hinge member 134 provided on the saw base 125, the hinge members being retained in place by a hinge pin 135. This added structure permits the saw to be tipped forward for grinding, cutting, or wire brushing an article held in a vise. Alternatively, the hinge plate may be made integral with the vise. Additionally, if the base of the saw does not already contain a hinge member 134, a separate hinge plate containing such member may be affixed to the saw base.

FIG. 16 shows a portion of an auxiliary handle 114 having a hand grip 115 in the form of a rearwardly disposed trapezoidal channel. A clamp member 116 having a V-shaped mandrel-engaging jaw 117 is affixed to the auxiliary handle 114 by means of bolts 118 and wing nuts 119. Clamped between the channel 115 and the mandrel engaging jaw 117 is a mandrel 120 having bearings 121 and a rotatable shaft 122. The front handle shown in FIG. 16 is provided as standard equipment on some commercially available saws, and is fixedly mounted thereon by welding or by rivets.

The apparatus of the present invention provides an attachment for converting hand-held power circular saws for use in drilling, sanding, and related operations. In a preferred form the apparatus is adapted to be mounted on the front auxiliary handle provided as standard equipment on some power saws. For those saws which do not havesuch a handle, the invention provides a handle which may be mounted on the base plate of standard saws by means such as bolts, and the auxiliary handle then utilized together with the clamping apparatus of the present invention to support a mandrel operated from the electric motor of the saw by means of pulleys and an endless belt.

While but several forms of the invention have been shown and described, other forms within the spirit and scope of the invention will now be apparent to those skilled in the art. Therefore, the embodiments shown in the drawings are to be considered as merely setting forth the invention for illustrative purposes and are not intended to limit the scope of the invention herein described and shown.

I claim:

1. A hand-held electric power-operated circular saw adapted to be utilized for operating power tool attachments comprising:

a. an integral base,

b. a motor mounted on said base having a rotatable shaft,

c. a handle mounted on said saw,

d. mandrel supporting means comprising an integral extension of said base directed upwardly therefrom and terminating in a mandrel-engaging recess, and means adjustably mounted on said mandrel supporting means cooperating with said mandrelengaging recess to engage and support a mandrel,

e. a mandrel mounted in said mandrel engaging recess and secured by said means adjustably mounted on said mandrel supporting means and having a shaft rotatably journaled therein,

f. a first pulley mounted on said mandrel shaft,

g. means at the end of said shaft for securing tool attachments thereto,

h. a second pulley affixed to the shaft of said motor.

and

i. a flexible endless belt operatively coupling said first and second pulleys.

2. A circular saw according to claim 1, wherein said means adjustably mounted on said mandrel supporting means comprises an adjustable clamp adapted to engage said mandrel.

3. A circular saw according to claim 1, wherein said mandrel comprises a sleeve having a bearing mounted at each end and wherein said mandrel shaft is journaled through said bearings.

4. An apparatus adapted to be utilized for operating power attachments comprising in combination:

a. an assembly from a hand-held electric poweroperated circular saw comprising:

1. a base.

2. a motor adjustably mounted on said base having a rotatable shaft,

3. a pulley mounted on said shaft,

4. a handle mounted on said saw, and

5. a front auxiliary handle comprising an upwardly extending support mounted on said base and having a channel-form handle grip, and

b. power tool attaching means comprising:

1. a clamping member comprising a support and a channel-form clamp jaw, and means for affixing said clamping member to said auxiliary handle, and

2. a mandrel having a shaft rotatably journaled therein, a pulley mounted on said shaft. and

means on said shaft for securing tool attachments thereto, the channel-form hand grip of said auxiliary handle and the clamp jaw of said clamping member cooperating to clamp said mandrel in place, and a flexible endless belt operatively mounted on said pulleys.

5. An apparatus according to claim 4, wherein said mandrel comprises a sleeve having a bearing mounted at each end and wherein said mandrel shaft is journaled through said bearings.

6. An apparatus according to claim 4, wherein one end of the base of said saw is provided with a plate hingedly connected thereto by means including a hinge pin, said plate being adapted to be secured to a workbench, and said saw being detachable from said plate wherein said handle is in the form of a loop. 

1. A hand-held electric power-operated circular saw adapted to be utilized for operating power tool attachments comprising: a. an integral base, b. a motor mounted on said base having a rotatable shaft, c. a handle mounted on said saw, d. mandrel supporting means comprising an integral extension of said base directed upwardly therefrom and terminating in a mandrel-engaging recess, and means adjustably mounted on said mandrel supporting means cooperating with said mandrel-engaging recess to engage and support a mandrel, e. a mandrel mounted in said mandrel engaging recess and secured by said means adjustably mounted on said mandrel supporting means and having a shaft rotatably journaled therein, f. a first pulley mounted on said mandrel shaft, g. means at the end of said shaft for securing tool attachments thereto, h. a second pulley affixed to the shaft of said motor, and i. a flexible endless belt operatIvely coupling said first and second pulleys.
 2. A circular saw according to claim 1, wherein said means adjustably mounted on said mandrel supporting means comprises an adjustable clamp adapted to engage said mandrel.
 2. a motor adjustably mounted on said base having a rotatable shaft,
 2. a mandrel having a shaft rotatably journaled therein, a pulley mounted on said shaft, and means on said shaft for securing tool attachments thereto, the channel-form hand grip of said auxiliary handle and the clamp jaw of said clamping member cooperating to clamp said mandrel in place, and a flexible endless belt operatively mounted on said pulleys.
 3. a pulley mounted on said shaft,
 3. A circular saw according to claim 1, wherein said mandrel comprises a sleeve having a bearing mounted at each end and wherein said mandrel shaft is journaled through said bearings.
 4. An apparatus adapted to be utilized for operating power attachments comprising in combination: a. an assembly from a hand-held electric power-operated circular saw comprising:
 4. a handle mounted on said saw, and
 5. a front auxiliary handle comprising an upwardly extending support mounted on said base and having a channel-form handle grip, and b. power tool attaching means comprising:
 5. An apparatus according to claim 4, wherein said mandrel comprises a sleeve having a bearing mounted at each end and wherein said mandrel shaft is journaled through said bearings.
 6. An apparatus according to claim 4, wherein one end of the base of said saw is provided with a plate hingedly connected thereto by means including a hinge pin, said plate being adapted to be secured to a workbench, and said saw being detachable from said plate by removal of said hinge pin.
 7. An apparatus according to claim 4, having a handle affixed to said mandrel to facilitate holding and manipulation when in operation.
 8. An apparatus according to claim 7, wherein said handle is in the form of a loop.
 9. An apparatus according to claim 4, wherein said front auxiliary is detachable from said base.
 10. A power tool attachment according to claim 9, having a handle affixed to said mandrel to facilitate holding and manipulation when in operation.
 11. A power tool attachment according to claim 10, wherein said handle is in the form of a loop. 